Seven minutes after President Obama put his signature to a landmark national health care insurance program, a lawyer in the office of Florida GOP attorney general Bill McCollum hit a computer key, sparking a legal challenge to the new law that would eventually reach the nation’s highest court. Health care is only the most visible and recent front in a battle over the meaning and scope of the U.S. Constitution. The battleground is the Supreme Court, and one of the most skilled, insightful, and trenchant of its observers takes us close up to watch it in action.